Problem: Complete the recursive formula of the arithmetic sequence $-3, -1, 1, 3,...$. $b(1)=$
The first term is $-3$ and the common difference is $2$. ${+2\,\curvearrowright}$ ${+2\,\curvearrowright}$ ${+2\,\curvearrowright}$ $-3,$ $-1,$ $1,$ $3,...$ This is the recursive formula of $-3, -1, 1, 3,...$ $\begin{cases} b(1)=-3 \\\\ b(n)=b(n-1)+2 \end{cases}$